Diurnal migration and responses to simulated rainfall in desert soil microarthropods and nematodes

TitleDiurnal migration and responses to simulated rainfall in desert soil microarthropods and nematodes
Publication TypeJournal Article
Year of Publication1981
AuthorsWhitford WG, Freckman D.W, Elkins NZ, Parker LW, Parmalee R, Phillips J, Tucker S
JournalSoil Biology and Biochemistry
Date Published1981
Call Number00397
Keywordsarticle, articles, journal, journals, microarthropod,diurnal migration, microarthropod,simulated rainfall, nematode,diurnal migration, nematode,rainfall simulation, rainfall simulation

Diurnal patterns of microarthropod abundance in surface leaf litter were related to its moisture content. Leaf litter moisture was nearly 7% by weight at 0800 h but fell to less than 1 % by mid-day. Oribatid and tydeid mites moved into litter in the early morning and back into the soil before mid-day. There were no significant differences in numbers of nematodes in litter or soil and 78098% of the nematodes were anhydrobiotic (coiled) in soil and litter at all times sampled. Following simulated rainfall there were fewer microarthropods in litter at mid-day in the absence of marked decreases in soil and litter moisture content. During drying, there were gradual reductions in numbers and species diversity of litter microarthropods. Nematode numbers did not change as litter dried. Anhydrobiotic nematodes in the soil increased from 14% on day 1 to 85% on day 4. Between 24 and 36 h after simulated rainfall, the proportion of anhydrobiotic litter nematodes increased from 35 to 80%. Within 1 h after simulated rainfall, there were marked increases in numbers and diversity of microarthropods in surface litter. No collembolans were extracted from dry litter controls but the wet litter was dominated by isotomid, sminthurid and onychiurid collembolans. There were increases in numbers and diversity of oribatid, tydeid and gamasid mites in the wet surface litter within 1 h after wetting compared to controls.